CHAPTER VI 



THE DEVELOPMENT OF EXPERIMENTAL RESEARCH AND ITS 

 APPLICATION TO COMPARATIVE BIOLOGY 



The development of organic chemistry 



IN THE PREVIOUS SECTION it has been pointed out that during the eighteenth 

 century the experimental method was applied with great success both in 

 animal and in vegetable biology; names such as Haller and Spallanzani, 

 Hales and Ingenhousz are sufficient proof of this. During the reign of roman- 

 tic natural philosophy, conditions were diff"erent; the representatives of that 

 school, who imagined that they could solve all the riddles of existence by 

 speculation, deeply scorned experiment, which they considered led to noth- 

 ing but fruitless artifice. Indeed, the physiological works which saw the 

 light during this epoch are for the most part purely speculative or else de- 

 voted to morphological problems. Gradually, however, reason came into 

 its own even in this sphere; the immense success which the experimental 

 method brought to contemporary physics and chemistry induced attempts 

 at applying that method also to biology. And this all the more so as during 

 the immediately preceding period eminent scientists had begun to apply 

 themselves with considerable success to the study of the chemical composi- 

 tion of living organisms. A glance at the development that had taken place 

 in that branch of chemistry may therefore not be out of place in this con- 

 nexion. 



Carl Wilhelm Scheele, mentioned in the previous section as a pioneer 

 in gas chemistry, is worthy to be called the founder also of animal and vege- 

 table chemistry. German in origin and upbringing — he was born at Stral- 

 sund in ij^i. — in his youth he adopted the profession of apothecary in 

 Sweden, finally settling at Koping, a small town, where he died in 1786. 

 During a brief life spent in very poor circumstances he managed to carry 

 out unusually fruitful research work. As one part of his work it may be 

 mentioned that he subjected to a more thorough chemical revision than any- 

 one had done before him elements from the animal and vegetable kingdom; 

 among the results he obtained was the discovery of lactic acid, cyanuric acid, 

 hydrocyanic acid, and uric acid, and, further, glycerine, citric acid, and malic 

 acid, not to mention other equally important elements. Lavoisier, it will be 

 remembered, also studied phenomena in the animal and vegetable kingdoms. 

 A successor to him was Antoine pRANgois de Fourcroy (175 5-1 809). 



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